Seamline Pacific BuildersInnovate. Build. Excel.

A builder’s discipline. An owner’s perspective.

Seamline Pacific Builders is a cost-certain, schedule-driven construction firm: general contracting, construction management and owner representation for owners and developers who value clarity, accountability and disciplined execution.

Leadership

  • Ryan Dumoulin

    Ryan Dumoulin

    President

  • Bill Lee

    Bill Lee

    Project Executive

  • Quentin Johns

    Quentin Johns

    Chief Financial Officer

What owners say

“I have known Ryan Dumoulin for more than ten years, and he is, without question, one of the most capable construction professionals I have had the privilege of working with. Most recently, we partnered on a large public works project for the City of Los Angeles in downtown LA, a job with real complexity, many stakeholders, and no room for error. Ryan ran it beautifully. From day one, the project was completely organized. The contracts were clear, thorough, and well written, which set expectations up front and kept every party aligned throughout. Subcontractors and vendors were paid on time, every time, and that kind of discipline builds trust and keeps a job moving. Ryan stayed on top of every detail and consistently anticipated problems before they became issues. The project was a complete success, and that success is a direct result of Ryan’s expertise, leadership, and integrity. He doesn’t just manage a project; he owns it. I recommend Ryan and Seamline Pacific Builders without reservation to any owner looking for a builder they can count on.”

Josh Hickman, President, Construction & Facilities, MAG Capital Partners

Specialized expertise

  • Healthcare and medical

    Occupied hospitals, correctional-medical and treatment facilities where infection control, life-safety and 24/7 uptime are non-negotiable.

  • cGMP, pharma and biotech

    Cleanrooms, controlled environments and validation-ready manufacturing built to exacting regulatory standards.

  • High-tech and laboratories

    Advanced facilities and lab build-outs demanding precision, cleanliness and specialized MEP systems.

  • Central plants and mechanical

    Central chilled-water plants, thermal energy storage (TES) and large-scale HVAC modernization.

  • Plumbing and process piping

    Building, process and life-safety piping executed in critical, occupied environments.

  • Large-scale multifamily

    Ground-up multifamily at scale.

Markets we serve

Commercial interiors and TI. Multifamily and mixed-use. Higher education, K-12 and campus. Healthcare, civic, correctional and aviation. Industrial facilities, distribution and logistics.

Prior leadership experience

Projects Ryan Dumoulin led in senior roles at previous firms. These are individual credentials of key personnel, not Seamline Pacific Builders, Inc. company past performance.

ProjectTypeLocationRyan’s role
Sunset + Vine TowerHigh-Rise / Mixed-UseHollywood, CAProject Executive
USC Galen CenterSports / ArenaLos Angeles, CAProject Executive
5600 WilshireMultifamilyLos Angeles, CAProject Manager
NRDC — Robert Redford BuildingCommercialSanta Monica, CAProject Manager
Doheny Eye InstituteHealthcare / MedicalPasadena, CAProject Executive - Mechanical Contractor
Kaiser Permanente South Bay Medical CenterHealthcare / MedicalSanta Ana, CAProject Management
EVOQ Properties OfficesCommercialLos Angeles, CAProject Executive
Santa Monica College — AET CampusHigher EducationSanta Monica, CAProject Executive - Mechanical Contractor
LAX — Security Systems IntegrationAviationLos Angeles, CAProject Management
CSU Long Beach — Central PlantHigher EducationLong Beach, CAProject Executive - Mechanical Contractor
CSU Dominguez Hills — Science & Innovation BuildingHigher EducationCarson, CAProject Executive
CSU Dominguez Hills — Innovation & Instruction BuildingHigher EducationCarson, CAProject Executive - Mechanical Contractor
CSU San Bernardino — Central PlantHigher EducationSan Bernardino, CAProject Executive - Mechanical Contractor
Pierce College — Advanced Automotive Technology BuildingHigher EducationWoodland Hills, CAProject Executive - Mechanical Contractor
Pierce College — Central PlantHigher EducationWoodland Hills, CAProject Executive - Mechanical Contractor
Cabrillo High School (LBUSD)K-12 EducationLong Beach, CAProject Management
LAUSD — Multiple Projects (13 total)K-12 EducationLos Angeles, CAProject Manager